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The brain is the most important and most complex part of the body. It controls almost all body processes including:
The brain is also responsible for memory, emotion, behavior, and reasoning. The health of the brain is vital to nearly everything we do.
The brain sits inside the skull, which protects it from injury. Between the skull and the brain are three layers of tissue called the meninges. They also help protect the brain and spinal cord.
The brain is an extremely complex structure. Each part of the brain serves its own specific function and works together with other parts of the brain to perform even more complex functions. The brain can be described in four main parts.
The brain stem is at the base of the brain and connects the cerebrum directly to the spinal cord. It controls many involuntary but necessary processes in the body, such as breathing, heart rate, swallowing, and blood pressure. The brain stem relays messages from the brain to other parts of the body. We cannot survive without it.
The cerebellum is located at the back of the brain. It’s responsible for movement, posture, and balance. Many of the motor functions that come from the cerebrum have to pass through the cerebellum before the body carries them out.
The limbic system is a collection of several structures at the center of the brain. These structures control emotion and memory.
The cerebrum forms the major portion of the brain. It’s divided into left and right halves, called hemispheres. The left hemisphere controls the right side of the body, and the right hemisphere controls the left side of the body. Each hemisphere is subdivided into four lobes:
One unfortunate consequence of the brain's complexity is that so many different things can go wrong with it. The National Institute of Neurological Disorders and Stroke (NINDS), for example, researches over 600 different neurologic diseases. There are several more common types of brain disorder.
Brain trauma may be caused by a number of things, including:
It usually happens suddenly and requires immediate treatment. A concussion, for example, is a sharp blow to the head that causes the brain to collide against the inside of the skull. Symptoms usually last for a few days and up to two week and can include:
Anyone who suffers a blow to the head needs to seek medical attention, even if they feel fine. There could be bleeding in the brain that may be fatal if not detected right away. More severe cases of traumatic brain injuries can lead to an extended period of unconsciousness (coma), or even death.
A brain aneurysm is a bulge in the wall of an artery in the brain. Common symptoms include:
If untreated, an aneurysm can rupture and cause a sudden, extremely severe headache or death. A ruptured aneurysm is a severe medical emergency.
A stroke is an interruption of blood flow to part of the brain caused by bleeding in the brain or by a blood clot clogging an artery. Stroke symptoms come on suddenly and may include:
If you experience symptoms of a stroke, it’s essential to seek medical attention as soon as possible. Prompt treatment can save areas of brain from permanent damage.
Degenerative brain diseases cause progressive damage to the parts of the brain that control cognition, emotion, and mobility. The damage tends to accumulate and increase over a long period of time.
The most common form of degenerative brain disease is dementia. People with dementia undergo a gradual loss of intellectual and cognitive abilities over time, but this typically doesn’t start until after age 60. The initial signs and symptoms of dementia may be subtle but can progress from lapses in memory to include:
Alzheimer’s disease is the most common form of dementia. Despite this, the exact cause is still unknown. Genetics is thought to play a role. Alzheimer’s disease and other types of dementia typically occur in older individuals. The risk increases as you age.
If you are concerned that a member of your family is beginning to show signs of dementia, it’s important to talk to a doctor. Several basic tests can help your doctor determine whether any of the symptoms are reversible and how to support the patient as they begin to deal with any new diagnosis.
Epilepsy is a disease that causes abnormal electrical discharges in the brain. The main symptom of epilepsy is repeated seizures, which are episodes of disturbed brain function. A seizure can manifest as one or more of the following symptoms:
The brain can also be affected by tumors, bacterial and viral infections, genetic diseases, metabolic conditions, and a number of other developmental disorders and conditions.
Like other parts of the body, your brain may lose some agility as you get older. Some brain conditions, like Alzheimer’s disease, may not be preventable. There are many things you can do now to help keep your brain healthier as you age. You can take certain precautions to reduce the risk of certain types of dementia or brain trauma, or delay the onset of dementia.
Additionally, the National Stroke Association (NSA) has published Stroke Prevention Guidelines to help reducing your risk of stroke. The guidelines include the following recommendations.
Written by: Healthline Editorial Team & Jacquelyn Cafasso
Medically reviewed on: Sep 04, 2014: Brenda B. Spriggs, MD, MPH, MBA
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